The present invention relates to a process for recovering waste heat which is particularly effective for recovering the heat lost in condenser water, condensate and flash steam from heat exchangers in a chemical distillation or other manufacturing process. All condensate from steam heated reboilers and all warm water from water cooled condensers, which would ordinarily be discharged to storm sewers, may be recycled through the process of the present invention to recover waste heat contained therein.
While steam recycling systems are not unknown, as for example, in steam engines and other waste heat recovery processes, the present invention provides an industrial scale waste heat recovery process offering remarkable efficiency and reduction in expense, wherein great quantities of ordinarily exhausted waste heat can be recovered economically and transmitted across an industrial site for reprocessing.
Chemical processes often utilize pressurized steam to aid in carrying out reactions, processes and distillations. Often, this steam is produced in a steam or power plant which is remotely located from the site of the chemical process since it may have to serve the needs of an entire manufacturing facility. Pressurized steam or hot water can be pumped to the process site and utilized, but expanded steam is ordinarily discharged as a waste product of the process.
With the condensate recovery system of the present invention, condensate from chemical distillation reboilers and warm water condensers can be collected while still hot and recycled to a steam plant where it may become the major source of boiler water depending upon the requirements of the steam plant.
If in a chemical process, pressurized steam is passed through a reaction mixture for intimate mixing, agitating, heating and pressurizing purposes, it is necessary that the boiler feed water at the steam generating plant be purified before it is converted to steam. For example, if the source of the boiler feed is river water it may contain unacceptable amounts of air, carbon dioxide and living or dead organic matter for a particular chemical process. Since the present invention recycles a significant amount of the hot pressurized steam condensate utilized in the chemical process, not only is there a substantial energy savings but additionally, the necessity and expense of purifying large amounts of boiler feed water can be dramatically reduced.
Operation of the present invention offers substantial benefits to those interested in increased energy efficiency. Recycling steam in the manner disclosed by the present invention serves to reduce the fuel consumption requirements of the boiler plant which produces the steam. Furthermore, not only is thermal pollution reduced in terms of pounds of steam released per hour, but also, damage to storm sewers where the steam would ordinarily be released is eliminated. Additionally, storm sewer and secondary water supply loading can be substantially decreased.
It is therefore an object of the present invention to provide a process for the efficient recovery of waste heat from a manufacturing process.
It is another object of the present invention to provide for recycling steam condensate in a distillation or manufacturing process.
It is another object to provide a process for supplying substantially pre-purified and pre-heated boiler feed water requirements.
These and other objects will become apparent upon careful consideration of the following specification taken in conjunction with the accompanying drawing.